In an autofocusing mechanism of a camera module in use for a mobile apparatus such as a mobile phone, a method of moving a lens has been typically available, and the development of a variety of actuators for activating such a lens movement has been also advanced on the premise of the lens driving.
On the other hand, in terms of the camera performance, the demand for making a lens aperture as large as possible has been created to achieve the higher sensitivity. However, reduction in size has been sought out as a module, and thus it has been difficult to meet such a demand by the use of a lens-drive actuator.
FIG. 1 is a diagram showing a small-sized camera module adopting a typical VCM (Voice Coil Motor) actuator method.
A camera module 1 illustrated in FIG. 1 has a lens system 2 that is formed of a plurality of lenses, a lens holder 3 that holds the lens system 2 with an optical axis thereof aligned, and a VCM actuator 4 including a yoke, magnet, and a coil that are all arranged on the outer circumferential side of the lens holder 3. The camera module 1 has a structure in which an image sensor 5 is attached to a substrate 7 that is arranged on a bottom surface 6B of a housing 6 of the camera module 1, and the lens system 2 is moved in the optical axis direction by the VCM actuator 4.